Cable regulator assemblies are well known, typically having a drive cable mounted onto one or more cable guides and driven by suitable drive means, for example, a drive drum mounted for reversible rotation by a hand crank, electric motor or the like. The drive cable is attached to a driven member at one or more locations, such that the position of the driven member can be controlled by actuating the drive means to controllably drive the cable. Cable regulators are widely used for controlling the position of a window pane, for example, a window pane vertically mounted in the window opening of a motor vehicle door. Exemplary cable window regulator assemblies for use in motor vehicles are shown in U.S. Pat. No. 4,910,917 to Bauer, entitled Bowden Cable Equipped Window Lift, and in earlier U.S. Pat. No. 4,110,935 to Sessa, entitled Cable-Actuated Car-Side-Window-Lifting Mechanism. Typically, the window pane is carried by one or more brackets fixedly attached to the cable.
Regulator assemblies in which a single carrying bracket is used may provide inadequate stability to the window, allowing it to rock or rotate in its lifting plane due to uneven edge resistance as the window pane is being raised or lowered. It is known that improvement can be obtained by dual mounting brackets attached to the window pane at spaced locations along its bottom edge, and each fixedly attached to the drive cable. Both the aforesaid Sessa patent and Bauer patent show regulator assemblies employing dual mounting brackets. The advantages of dual guide rails for motor vehicle window regulators are recognized, for example, in commonly owned U.S. Pat. No. 5,398,449 to Kobrehel et at, entitled Window Regulator for a Frameless Door Assembly.
Significant difficulties have been experienced, however, using cable regulator assemblies having such dual mounting brackets if the brackets are not lifted and lowered along precisely parallel paths. The Bauer patent suggests designs to correct or compensate for misalignment of the guide rails along which two window pane mounting brackets travel. The two guide rails are mounted separately in a vehicle door, and the compounding of manufacturing tolerances and assembly variability leads to lack of adequate parallelism of the two guide mils. Consequently, the Bauer patent suggests that only one mounting bracket be rigidly fixed to the window pane while the other employs a mounting slot or eccentric cam to accommodate such misalignment, leading to reduced window pane stability.
Alternative cable regulator designs present significant assembly disadvantages. The structural members of a vehicle door forming the door cavity in which the regulator assembly is to be mounted, typically prevent installation into the cavity of a pre-assembled cable regulator assembly. In addition, the typically small working area within the door cavity and its limited access from the outside inhibit assembly inside the door cavity.
It is an object of the present invention to provide a cable regulator assembly having improved installation capability. It is a further object of the invention to provide a regulator assembly which at least in preferred embodiments provides dual guide rails interconnected by a rigid joining member for improved parallelism between the guide rails, and yet which has the aforesaid improved installation capabilities. Additional objects and features of the invention will become apparent from the following disclosure taken together with the detailed discussion of certain preferred embodiments.